Plasma Concentration of Cortisol Negatively Associates with Platelet Reactivity in Older Subjects

The interaction of platelets with steroid hormones is poorly investigated. Age is one of the factors that increase the risk of pathological platelet reactivity and thrombosis. The aim of this study was to assess whether there were associations between platelet reactivity and plasma cortisol levels in volunteers aged 60–65 years. For this purpose, impedance aggregometry in whole blood measured after arachidonic acid, collagen, or ADP stimulation was used to estimate platelet reactivity and mass spectrometry was used to measure peripheral plasma cortisol concentration. Statistically significant negative correlations were observed between cortisol concentration and platelet reactivity in response to arachidonic acid and ADP, but not to collagen. The presented results suggest for the very first time that cortisol is a new endogenous modulator of platelet reactivity in the elderly population.     

Toward 20 T magnetic resonance for human brain studies: opportunities for discovery and neuroscience rationale

Magnetic Resonance Materials in Physics, Biology and Medicine - An initiative to design and build magnetic resonance imaging (MRI) and spectroscopy (MRS) instruments at 14 T and beyond to...     

Antibacterial and Cytotoxicity Evaluation of New Hydroxyapatite-Based Granules Containing Silver or Gallium Ions with Potential Use as Bone Substitutes

The aim of the current work was to study the physicochemical properties and biological activity of different types of porous granules containing silver or gallium ions. Firstly, hydroxyapatites powders doped with Ga³⁺ or Ag⁺ were synthesized by the standard wet method. Then, the obtained powders were used to fabricate ceramic microgranules (AgM and GaM) and alginate/hydroxyapatite composite granules (AgT and GaT). The ceramic microgranules were also used to prepare a third type of granules (AgMT and GaMT) containing silver or gallium, respectively. All the granules turned out to be porous, except that the AgT and GaT granules were characterized by higher porosity and a better developed specific surface, whereas the microgranules had very fine, numerous micropores. The granules revealed a slow release of the substituted ions. All the granules except AgT were classified as non-cytotoxic according to the neutral red uptake (NRU) test and the MTT assay. The obtained powders and granules were subjected to various antibacterial test towards the following four different bacterial strains: Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Escherichia coli. The Ag-containing materials revealed high antibacterial activity.     

Micro-RNAs in Response to Active Forms of Vitamin D3 in Human Leukemia and Lymphoma Cells

Non-coding micro-RNA (miRNAs) regulate the protein expression responsible for cell growth and proliferation. miRNAs also play a role in a cancer cells’ response to drug treatment. Knowing that leukemia and lymphoma cells show different responses to active forms of vitamin D₃, we decided to investigate the role of selected miRNA molecules and regulated proteins, analyzing if there is a correlation between the selected miRNAs and regulated proteins in response to two active forms of vitamin D₃, calcitriol and tacalcitol. A total of nine human cell lines were analyzed: five leukemias: MV-4-1, Thp-1, HL-60, K562, and KG-1; and four lymphomas: Raji, Daudi, Jurkat, and U2932. We selected five miRNA molecules—miR-27b, miR-32, miR-125b, miR-181a, and miR-181b—and the proteins regulated by these molecules, namely, CYP24A1, Bak1, Bim, p21, p27, p53, and NF-kB. The results showed that the level of selected miRNAs correlates with the level of proteins, especially p27, Bak1, NFκB, and CYP24A1, and miR-27b and miR-125b could be responsible for the anticancer activity of active forms of vitamin D₃ in human leukemia and lymphoma.     

Identification of Corosolic and Oleanolic Acids as Molecules Antagonizing the Human RORγT Nuclear Receptor Using the Calculated Fingerprints of the Molecular Similarity

RORγT is a protein product of the RORC gene belonging to the nuclear receptor subfamily of retinoic-acid-receptor-related orphan receptors (RORs). RORγT is preferentially expressed in Th17 lymphocytes and drives their differentiation from naive CD4+ cells and is involved in the regulation of the expression of numerous Th17-specific cytokines, such as IL-17. Because Th17 cells are implicated in the pathology of autoimmune diseases (e.g., psoriasis, inflammatory bowel disease, multiple sclerosis), RORγT, whose activity is regulated by ligands, has been recognized as a drug target in potential therapies against these diseases. The identification of such ligands is time-consuming and usually requires the screening of chemical libraries. Herein, using a Tanimoto similarity search, we found corosolic acid and other pentacyclic tritepenes in the library we previously screened as compounds highly similar to the RORγT inverse agonist ursolic acid. Furthermore, using gene reporter assays and Th17 lymphocytes, we distinguished compounds that exert stronger biological effects (ursolic, corosolic, and oleanolic acid) from those that are ineffective (asiatic and maslinic acids), providing evidence that such combinatorial methodology (in silico and experimental) might help wet screenings to achieve more accurate results, eliminating false negatives.     

Physicochemical and sensory properties of goat cheeses and their fatty acid profile in relation to the geographic region of production

The aim of the study was to evaluate the chemical composition, colour and sensory profile of rennet goat cheeses, taking into account their geographic region of production. The relationships between the botanical composition of the goats’ pasture to the fatty acid (FA) profiles and health indicators of the fat of cheese produced from their milk in artisanal conditions were also determined. Grazing of goats on natural pastures with greater floristic richness and, above all, the presence of more meadow species and herbs, not only increased the proportions of beneficial FAs in the cheese but also improved sensory characteristics valued by consumers.     

Total phenolic and total flavonoid content,antioxidant activity and sensory evaluation of pseudocereal breads

The aim of the study was to investigate the effect of adding (in two different doses 15% and 30%) pseudocereal (buckwheat, amaranth and quinoa) flour on the antioxidant properties and sensory value of breads. Buckwheat flour had the highest phenolic content (7.25 ± 0.23 mg/g dw). The content of total flavonoids in flours was about 2–4 fold higher when compared to breads. The addition of buckwheat flour to wheat bread, particularly in higher dose, was more effective in enhancing antioxidant activity, as evaluated by means of FRAP and DPPH, which increased by 2.36 fold, and 3.64 fold respectively, in comparison with other pseudocereal flours (amaranth, quinoa), which caused, in higher doses, the changes of above parameters within the ranges 1.20–1.79 fold, and 0.60–1.71 fold. Analysis of sensory results of breads showed that addition of buckwheat flour to the dough might improve subjective properties of bread and increase acceptable quality attributes such as taste, colour or odour. All these observations suggest that addition of buckwheat flour into bread can improve antioxidant as well as sensory properties of bread. Bread fortified with pseudocereal flours, and especially with buckwheat flour, may be placed on the market as a functional food.     

Kinetics of adenovirus type 2 inactivation with free chlorine

The objective of this study was to elucidate the effects of pH, temperature, and other relevant water quality parameters on the kinetics of adenovirus serotype 2 inactivation with free chlorine. Over a pH range of 6.5-10, a temperature range of 1-30 °C, and in a variety of water types, free chlorine was highly effective against adenovirus type 2. Its disinfection efficacy decreased with increasing pH and decreasing temperature, yet was unaffected by hardness and buffering species. Under the most challenging conditions investigated in this study (pH 10, 1 °C), a four-log reduction of adenovirus viability would be achieved at a CT value of 2.6 mg Cl₂ min/L. The inactivation kinetics was characterized by three phases of inactivation under most conditions. The first phase resulted from a reaction involving primarily the hypochlorous acid species and was characterized by rapid inactivation of viruses to a limit that increased with decreasing pH and increasing temperature. After reaching this limit, adenovirus exhibited two subsequent phases of inactivation at lesser rates that were not affected by temperature or pH. As with the first phase of kinetics, a limit of inactivation was approached in the second phase that decreased with increasing pH, and after which the kinetics was characterized by a third and final phase. An inactivation model consistent with these observations was found to provide adequate representation for the free chlorine inactivation of adenovirus serotype 2 as well as that reported in the literature for other adenovirus serotypes.     

Electron spin resonance studies on silver atoms in imogolite fibers

The formation and stabilization of reduced silver species in imogolite have been studied by electron spin resonance (ESR) spectroscopy. Ag-loaded imogolite samples after degassing and dehydration were γ-irradiated at 77 K and monitored by ESR as the temperature increased. Some samples were exposed to methanol vapour after dehydration. It was found that imogolite shows exceptional ability to stabilize silver atoms. In dehydrated Ag-imogolite silver atoms generated at low temperature remain stable at room temperature. Silver atoms are also formed in imogolite samples exposed to methanol. However, in contrast to silver agglomeration in molecular sieves and smectites exposed to methanol there is no indication of the formation of cationic silver clusters in Ag-imogolite. It is postulated that there are special trapping sites in imogolite structure which effectively stabilize silver atoms.